JP2003066024A - Discoloring pigment composition containing super absorbent polymer microspheres carrying discoloring pigments, method for producing the same, and antiforgery sheet using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition, a method for producing the same, and an antiforgery sheet using the same, wherein the composition is inexpensive and has good preservability, and can easily be applied on an object by printing, the composition being used for detecting the presence or absence of gaseous oxygen or performing authentication judgment without the use of a special authentication device. SOLUTION: A discoloring pigment composition is used, prepared by dispersing in an oil dispersion medium super absorbent polymer microspheres absorbing a solution and/or a dispersion of discoloring pigments which can reversibly change color tones by the presence or absence of oxygen. This discoloring pigment composition is used for creating an identification sign for authentication judgment on a predetermined part of at least one side of a base material. Color tone changes by the presence or absence of oxygen are confirmed visually or by an optical mechanical reading.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a variable color dye composition containing superabsorbent polymer fine particles carrying a variable color dye,
Anti-counterfeit sheet using the manufacturing method and the anti-counterfeiting property using the method (for example, receipts, forms such as securities, I
C card, magnetic card, rewrite card, etc.).

[0002]

2. Description of the Related Art Conventionally, for the purpose of making counterfeiting difficult, an ink containing a high-brightness pigment such as a titanium coating mica or a holographic label or a bright label attached to a specific portion of the base surface of foams and cards. There are things such as printed (pearl ink etc.). These are excellent in that they are not easily counterfeited and do not require a special authenticity judging device, but they are expensive, and therefore there is a problem that the manufacturing cost increases. On the other hand, there is a method of printing marks etc. with special fluorescent ink.According to this method, the mark is hidden in the normal state without increasing the manufacturing cost and the complexity of the manufacturing process. Although it is excellent in that it cannot be prevented, this type of special fluorescent ink may have a light color tone and may be difficult to distinguish. In addition, a black light irradiation device is required for authenticity judgment.
These authenticity determination techniques have a problem that when they have been technically established and have been generally recognized and publicized, they are likely to be counterfeited.

[0003]

SUMMARY OF THE INVENTION A first object of the present invention is to provide a composition containing a variable color dye whose color tone reversibly changes depending on the presence or absence of oxygen. A coating film can be formed by printing on an object, and the color tone reversibly changes depending on the presence or absence of oxygen to detect the presence or absence of oxygen gas, and to determine the authenticity of the object. The second object of the present invention is to provide a method for easily producing such a composition, and the third object of the present invention is to provide A forgery-preventing sheet having an identification code for authenticity determination formed on a predetermined portion of a base material using such a composition, at the time of authenticity determination, can be easily and easily confirmed by visual observation or optical mechanical reading, Furthermore, it is excellent in concealing the identification code for authenticity judgment. In addition, it said high difficulty of counterfeit goods creation and the genuineness tampering is to provide an anti-counterfeit sheet of a new method which is excellent in cost and productivity.

[0004]

Means for Solving the Problems As a result of earnest research for solving the above-mentioned problems, the present inventor has found that the presence or absence of oxygen, which has been conventionally used as an oxygen indicator for confirming the oxygen state in a hermetically-sealed package. A solution or dispersion of a variable color dye whose color tone reversibly changes is absorbed by superabsorbent polymer fine particles, and the superabsorbent polymer fine particles are dispersed in an oil dispersion medium to stabilize the variable color dye. It was found that a variable color dye composition to be retained can be obtained, and by using this composition to form an identification code for authenticity judgment on various foams and cards by printing etc. They have found that a sheet can be provided, and have completed the present invention.

That is, the identification code for authenticity determination formed with such a variable color dye composition is
Due to the presence of oxygen in the air, the color tone is maintained at the color tone in the aerobic state. However, by exposing this authenticity determination code in an atmosphere with no oxygen (or extremely low), the color tone becomes aerobic. It was confirmed that a method of changing the color tone in the state from the color tone in the anoxic state and confirming the change in the color tone by visual inspection or optical mechanical reading is an effective means for authenticity determination.

Further, the identification code for authenticity determination is covered with an oxygen impermeable transparent film so as to maintain the color tone in the anoxic state. At the time of authenticity determination, the transparent film is peeled or damaged. By contacting oxygen in the atmosphere with the variable color dye composition, the color tone of the authenticity determination code is changed to the color tone in the aerobic state, and this color tone change is visually confirmed or confirmed by optical mechanical reading. It was confirmed that the method is an effective means of authenticity judgment.

A variable color pigment composition containing superabsorbent polymer fine particles carrying a variable color pigment according to claim 1 of the present invention is a solution of a variable color pigment whose color tone is reversibly changed depending on the presence or absence of oxygen and / or It is characterized in that superabsorbent polymer fine particles having absorbed the dispersion liquid are dispersed in an oil dispersion medium.

The variable color dye composition containing the superabsorbent polymer particles carrying the variable color dye according to claim 2 of the present invention is the variable color dye composition according to claim 1, wherein the superabsorbent polymer particles are spherical. It is characterized by being fine particles.

A third aspect of the present invention includes the following steps (1) to (1).
(3) A method for producing a variable color dye composition containing fine particles of highly water-absorbing polymer carrying a variable color dye, which is characterized by being produced. (1) A solution and / or a dispersion is prepared by dissolving and / or dispersing a variable color dye whose color tone reversibly changes depending on the presence or absence of oxygen. (2) The superabsorbent polymer fine particles are allowed to absorb the solution and / or dispersion prepared in the step (1). (3) The super absorbent polymer particles prepared in step (2) are dispersed in an oil dispersion medium to prepare a variable color dye composition containing super absorbent polymer particles carrying a variable color dye.

According to claim 4 of the present invention, an identification code for authenticity determination formed by using the variable color dye composition according to claim 1 or 2 is provided on a predetermined portion of at least one surface of the substrate. It is the anti-counterfeit sheet.

According to a fifth aspect of the present invention, in the forgery prevention sheet according to the fourth aspect, at least a part of the identification code for authenticity determination is covered with an oxygen-impermeable transparent film so as to be in an oxygen-free state. The color tone of the variable color dye composition in the covered region exhibits the color tone in the anoxic state.

According to a sixth aspect of the present invention, in the anti-counterfeit sheet according to the fourth aspect, when the authenticity determination is performed, the identification code for authenticity determination is exposed to an atmosphere containing no oxygen.
The color tone of the variable color dye composition is changed from a color tone in an aerobic state to a color tone in an anoxic state, and the change in color tone can be visually recognized or optically mechanically read.

According to a seventh aspect of the present invention, in the anti-counterfeit sheet according to the fifth aspect, the area covered by the oxygen impermeable transparent film to be in an oxygen-free state at the time of authenticity judgment contains oxygen. When exposed to an atmosphere containing, the color tone of the variable color pigment composition in the coated area changes from the color tone in the anoxic state to the color tone in the aerobic state, and the color tone change can be visually or optically mechanically read. It is characterized by being.

The variable color dye composition containing the superabsorbent polymer fine particles carrying the variable color dye of the present invention is, for example, a highly water-absorbent solution in which a solution of the variable color dye whose color tone is reversibly changed depending on the presence or absence of oxygen is absorbed. Since it is a dispersion of fine polymer particles in an oil dispersion medium, it is inexpensive and has good storage stability.
In addition to being easily applied to the object by a known method such as printing,
For detecting the presence or absence of oxygen gas by utilizing the fact that the variable color dye absorbed in the super absorbent polymer particles in the coating film reversibly changes the color tone depending on the presence or absence of oxygen, and for the authenticity judgment of the object. Available.

By the production method of the present invention, a variable color dye composition containing the superabsorbent polymer fine particles carrying the variable color dye of the present invention can be easily produced.

The anti-counterfeit sheet of the present invention is inexpensive and has good storability, and the identification code for authenticity determination is formed on a predetermined portion of at least one surface of the substrate by using the variable color dye composition, When exposed to an atmosphere containing no oxygen, the color tone of the variable color pigment composition changes from the color tone in the aerobic state to the color tone in the anoxic state, and the color tone change can be visually recognized or optically mechanically read. . According to the anti-counterfeit sheet of the present invention having such a configuration, the identification code for authenticity determination,
Due to the presence of oxygen in the air, it has a color tone in the aerobic state, but at the time of authenticity judgment, a forgery prevention sheet is stacked in the vacuum chamber and nitrogen gas etc. is selectively used as an identification code for authenticity judgment. The authenticity determination identification code is exposed to the atmosphere without oxygen (or extremely low) by changing the color tone from the color tone in the aerobic state to the color tone in the anoxic state. Therefore, the genuine product can be confirmed by visually confirming the change in color tone or by optical mechanical reading. In other words, such a phenomenon does not occur in a counterfeit product in which an authenticity determination identification code is formed with normal printing ink, so that it can be immediately confirmed that the product is a counterfeit product.

It is also possible to improve the concealment property by applying a special treatment to the authenticity determining identification code. For example, the color tone in the aerobic state of the identification code for authenticity determination and its surrounding area are colored by using a general ink of the same color as this color tone, so that the code in the state placed in the atmosphere The contour shape of is indistinguishable and the concealment is enhanced.

In another anti-counterfeit sheet of the present invention, at least a part of the identification code for authenticity determination is covered with an oxygen-impermeable transparent film so as to be in an oxygen-free state. The color tone of the variable color pigment composition exhibits the color tone in the anoxic state, and in the authenticity determination, the region covered by the oxygen impermeable transparent film to be in the anoxic state is a transparent film. When exposed to an atmosphere containing oxygen by peeling or breaking, the color tone of the variable color dye composition in the coated region changes from an anoxic color tone to an aerobic color tone, The change in color tone can be visually recognized or read by optical machine. In a counterfeit product in which an authenticity identification code is formed with normal printing ink, such a phenomenon does not occur, so even if the transparent film is peeled or damaged, the color tone does not change and it is a counterfeit product. You can check immediately.
Furthermore, this variable color dye composition itself is not common compared to the fluorescent substances contained in conventional fluorescent inks and has a high degree of speciality, and it is difficult to attach a transparent film in an oxygen-free state. Creating a product is very difficult.
In addition, if you try to tamper with the genuine product and then peel off the transparent film, the authenticity determination code will change to the color tone of the aerobic state. Due to the difficulty of reattaching the transparent film in the state where the code is returned to the anoxic color tone, it is extremely difficult to forge by falsification.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in detail based on the embodiments. As the super absorbent polymer used in the present invention, starch-based, cellulose-based or acrylamide, acrylic acid, acrylic acid salt, methacrylic acid salt,
Polymers such as styrene and vinyl ether, copolymers,
Examples thereof include synthetic resin systems such as terpolymers. As commercially available products, for example, nonionic polyalkylene oxide superabsorbent polymer "AQUACALK" (manufactured by Sumitomo Seika)
Since the water absorption does not change even with salt, it can be suitably used. Among the super absorbent polymers, there are water-soluble, pasty, or water-swellable particles, crushed particles, granular particles, and powder particles when absorbing water. But you can use it.

As the highly water-absorbent polymer showing a strip shape,
Specifically, a solution of a monomer containing acrylic acid and an ammonium salt of acrylic acid or an alkali metal salt is added with 0.1
10% by mass of a polyvalent organic metal ion crosslinking agent is added, solution polymerization is performed, and an appropriately crosslinked superabsorbent polymer obtained by drying, or an acrylic acid and an ammonium salt or an alkali metal salt of acrylic acid An example is a suitably water-absorbent polymer which is obtained by post-crosslinking the copolymer with 0.1 to 10% by mass of a polyvalent organic metal ion crosslinking agent.

The superabsorbent polymer exhibiting a crushed, granular or powdery state is obtained by pulverizing the superabsorbent polymer into a predetermined particle shape, or polymerizing or condensing the raw material compound of the superabsorbent polymer. Then, a method of forming the polymer compound in a granular form is exemplified. Among them, spherical or granular polyacrylic acid salt obtained by reverse phase suspension polymerization in an organic solvent, a method of saponifying a vinyl alcohol / acrylic acid salt copolymer or an isobutylene / maleic anhydride copolymer. The resulting superabsorbent polymer (for example, average particle size of about 0.005 to 5 mm) is preferably used because even if water is absorbed, the particles remain non-adhesive to each other and maintain independent particles in a water-retaining state. it can.

A superabsorbent polymer which maintains independent particles even in a water-retaining state can absorb a large amount of a solution or dispersion liquid with high absorbency rapidly, and even if absorbed, it becomes sticky or lumps. Easy to use and handle without sagging.

The particle size of the superabsorbent polymer fine particles used in the present invention is not particularly limited, and may be of the nm order (molecular dispersion system) depending on the application, type of product, or nm-μm. It may be of the order (colloidal dispersion system), or of μm or larger (coarse particle dispersion system), or a mixture of two or more thereof.

The variable color dye used in the present invention reversibly and clearly changes its color tone in an atmosphere having an oxygen concentration that is contained in ordinary air and in an oxygen-free state, and the color tone thereof is changed. The change can be visually confirmed or confirmed by an optical mechanical reading device (visible light region compatible). Therefore, as long as this change in color tone is reversible, any variable color pigment can be used, but it is preferable to use a so-called oxygen indicator conventionally used for confirmation of the anoxic state in a sealed package. What is used is good. The variable color dye used for the oxygen indicator generally comprises a redox dye and a reducing agent for the redox dye, an alkaline substance and water, and is prepared as an aqueous or oily dye. To be done.

In such a variable color dye, a reversible change in color tone occurs according to the oxygen concentration, but the main cause is that the redox dye is in a state of being oxidized in an environment where the oxygen concentration is high. However, when placed in the anoxic state, the state of being once oxidized is changed to the state of being reduced by the action of the coexisting reducing agent. This oxidation / reduction is reversible, the coexisting reducing agent is consumed, and the reversibility is maintained until it is exhausted. The alkaline substance and water are used to form a field for this oxidation / reduction reaction and to maintain the alkalinity, which is a pH range that induces a color tone change accompanying the reaction.

As the redox dye, Japanese Patent Publication No.
JP-A-5-47820, JP-B-56-24906, JP-A-56-8647 and the like, thiazine dyes such as methylene blue, indico dyes such as potassium indicosulfonate, thioindigo dyes and the like. Further, the indophenol dyes described in JP-A-2-138866 can be used.
In particular, this indophenol-based dye is much more preferable than the methylene blue-based dye, as the degree of fading is significantly less than that of the methylene blue-based dye even when it is left for a long time under irradiation with light. Glucose, fructose, and the like are used as reducing agents when reducing the oxidant of such a redox dye.
It is preferable to use reducing sugars such as xylose and maltose. Since the reduction with the reducing sugar proceeds under alkaline conditions, it requires an alkaline substance such as magnesium hydroxide and a small amount of water.

An example of a variable color dye using a methylene blue dye is shown below. The redox dye methylene blue and the reducing saccharide D-glucose are used as alkaline dyes. As the substance, magnesium hydroxide which does not have properties such as deliquescent property and high water absorption was selected, and the necessary water was added to the composition.

[Example of Variable Color Dye Composition Utilizing Methylene Blue Dye] Magnesium hydroxide 96.95 parts by mass D-glucose 1.0 part by mass Methylene blue 0.05 parts by mass water 2.0 parts by mass

Furthermore, an example of a variable color dye using an indophenol dye will be shown below. The redox dye 2,6-dichloroindophenol sodium salt and the reducing sugar D-glucose were used as the reducing agent, sodium carbonate was added as the alkaline substance, and the necessary water was added thereto. The composition. Also, in this example, methyl alcohol is added as a solvent in order to make the whole solution. It should be noted that 2,6-dichloroindophenol sodium salt itself becomes almost colorless (white) in the anoxic state, so Acid Red (food red 10
No. 6) as an indicator dye gives a red color tone in the anoxic state and a blue color tone in the aerobic state.

[0030] [Example of variable color dye composition using indophenol dye]     2,6-dichloroindophenol sodium salt 0.5 part by mass     Acid Red (Edible Red No. 106) 0.1 parts by mass     Sodium carbonate 25.0 parts by mass     D-glucose 2.0 parts by mass     2.0 parts by mass of water     Methyl alcohol 70.4 parts by mass

The oil-based dispersant used in the present invention is hexane or cyclohexane as long as it can prepare a variable color dye composition by dispersing a solution of variable color dye and / or fine particles of a super absorbent polymer having absorbed the dispersion liquid. ,Carbon tetrachloride,
Chloroform, dichloromethane, dichloroethane, diethyl ether, 1,2-dimethoxyethane, tetrahydrofuran, 1.4-dioxane, ethyl acetate, N, N-
Dimethylformamide, hexamethylphosphoramide,
Acetone, acetonitrile, methanol, ethanol,
A low molecular weight organic compound such as an aliphatic solvent such as nitromethane, dimityl sulfoxide or sulfolane, an aromatic solvent such as benzene, toluene, naphthalene, chlorobenzene, anisole, diphenyl ether, pyridine or nitrobenzene, an oligomer or a polymer, or one or more of these. It may be a mixture and is not particularly limited.

As another example of the oily dispersant used in the present invention, a non-aqueous vehicle can be mentioned. The non-aqueous vehicle may be the solvent, the non-aqueous ink or the like, or a mixture thereof, and is not particularly limited. Specific examples of the non-aqueous ink include albumin, gelatin, casein, starch, gum arabic, natural resins such as sodium alginate, cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose, polyamide, polyacrylamide, polyhydroxyethyl methacrylate. , Polyphenylacetoacetal, polyethyleneimine, polyvinylpyrrolidone, polyvinylpyridinium halide, melamine resin, polyurethane, polyvinyl alcohol and its derivatives, polyester, sodium polyacrylate, synthetic resin such as acrylic acid ester copolymer, dimethylamine epichlorohydrin Polycondensate, acrylamide / diallylamine copolymer, polyvinylamine copolymer, dicyandiamide, dimethyl
An ink using a cationic resin such as a compound containing diallyl ammonium chloride as a main component or a mixture of two or more thereof can be mentioned. In addition, an electron beam curable ink, an ultraviolet curable ink, an anionic resin such as a rosin-modified maleic acid having an anionic group such as a sulfonic acid group, a carboxyl group, a sulfuric acid ester group, a phosphoric acid ester group or the like may be used as necessary. Can be used.

Of these, electron beam curable ink and ultraviolet curable ink can be preferably used in the present invention. Such electron beam curable and ultraviolet curable inks include
Any known acrylic photopolymerizable monomer and / or acrylic photopolymerizable oligomer can be arbitrarily selected and used.

Examples of the photopolymerizable monomer include unsaturated carboxylic acids such as acrylic acid and methacrylic acid or esters thereof such as alkyl-, cycloalkyl-, halogenated alkyl-, alkoxyalkyl-, hydroxyalkyl- and aminoalkyl-. , Tetrahydrofurfuryl-, allyl-, glycidyl-, benzyl-, phenoxy-acrylates and methacrylates, alkylene glycols, polyoxyalkylene glycol mono- or diacrylates and methacrylates, trimethylolpropane triacrylate and methacrylates, pentaerythritol tetraacrylate and Acrylamide, methacrylamide, or derivatives thereof such as methacrylate, for example, acryl mono- or di-substituted with an alkyl or hydroxyalkyl group. Amide and methacrylamide, diacetone acrylamide and methacrylamide, N, N '
Allyl compounds such as alkylene bis acrylamide and methacrylamide, such as allyl alcohol, allyl isocyanate, diallyl phthalate, triallyl isocyanurate and the like.

For applications where curing shrinkage is an obstacle, for example, isobornyl acrylate or methacrylate, norbornyl acrylate or methacrylate, dicyclopentenoxyethyl acrylate or methacrylate, dicyclopentenoxypropyl acrylate or Acrylate or methacrylic acid ester of diethylene glycol dicyclopentenyl monoether such as methacrylate, polyoxyethylene or polypropylene glycol dicyclopentenyl monoether acrylic acid ester or methacrylic acid ester, such as dicyclopentenyl cinnamate, dicyclopentenoxy Ethyl cinnamate, dicyclopentenoxyethyl monofumarate or difumarate such as 3,9-bis (1,1
-Bismethyl-2-oxyethyl) -spiro [5,5]
Undecane, 3,9-bis (1,1-bismethyl-2-
Oxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, 3,9-bis (2-oxyethyl) -spiro [5,5] undecane, 3,9-bis (2-oxyethyl) Mono-, diacrylate or mono-, dimethacrylate such as -2,4,8,10-tetraoxaspiro [5,5] undecane, or mono-, ethylene oxide or propylene oxide addition polymer of these spiroglycols, Diacrylate, mono- or dimethacrylate, or methyl ether of the monoacrylate or methacrylate, 1-azabicyclo [2,2,2] -3-octenyl acrylate or methacrylate, bicyclo [2,2,1] -5 -Heptene-2,3-dicarboxyl monoallyl ester, such as dicyclopenta Enyl acrylate or methacrylate, it can be used a photopolymerizable monomer, such as dicyclopentadienyl oxyethyl acrylate or methacrylate, dihydrodicyclopentadienyl acrylate or methacrylate. These photopolymerizable monomers may be used alone or in combination of two or more.

As the acrylic photopolymerizable oligomer,
Acrylic acid ester of epoxy resin such as diglycidyl ether diacrylate of bisphenol A, reaction product of epoxy resin with acrylic acid and methyltetrahydrophthalic anhydride, reaction product of epoxy resin with 2-hydroxyethyl acrylate, glycidyl diacrylate Ring-opening copolymerization ester of acrylate and phthalic anhydride, ester of methacrylic acid dimer and polyol, polyester obtained from acrylic acid, phthalic anhydride and propylene oxide, reaction product of polyvinyl alcohol and N-methylolacrylamide An unsaturated polyester prepolymer such as a reaction product of polyethylene glycol, maleic anhydride and glycidyl methacrylate, or the like, after esterifying polyvinyl alcohol with succinic anhydride,
Such as polyvinyl alcohol prepolymers such as those with glycidyl methacrylate added, reaction products of methyl vinyl ether-maleic anhydride copolymer and 2-hydroxyethyl acrylate, or those further reacted with glycidyl methacrylate Polyacrylic acid or maleic acid copolymer-based prepolymers, etc., as well as urethane-based prepolymers having acryloyl groups or methacryloyl groups at both ends linked to polyoxyalkylene segments and / or saturated polyester segments via urethane bonds, etc. Can be mentioned. These acrylic photopolymerizable oligomers are
A weight average molecular weight of about 2000 to 30,000 is suitable.

The photopolymerization initiator may be a conventionally known one, for example, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1.
-Phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-methyl-1-propan-1-one, 2-methyl-1- [4
-(Methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1
-(4-morpholinophenyl) -butanone-1-bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide-bis (2,2
4,6-trimethylbenzoyl) -phenylphosphine oxide and the like can be mentioned. These photopolymerization initiators may be used alone or in combination of two or more. Its content is usually 10 vehicles.
It is preferably selected in the range of 5 to 15 parts by mass per 0 parts by mass.

The variable color pigment composition of the present invention containing the super absorbent polymer particles carrying the variable color pigment can be easily produced by the following steps (1) to (3). First, in step (1), a solution and / or dispersion in which a variable color dye is dissolved and / or dispersed in a solvent is prepared. In the present invention, a surfactant may be used when dispersing the variable color dye in a solvent.
LB, the amount used, etc. are not particularly limited, and include anionic surfactants, nonionic surfactants, cationic surfactants,
Any amphoteric surfactant or the like can be used. The addition amount of the variable color dye to the solvent is not particularly limited as long as it can be stably maintained for a long time, and may be an addition amount that can stably maintain the dispersed state.
The method and apparatus for dissolving or dispersing in a solvent are not particularly limited, and known ones can be used.

Next, in step (2), the solution and / or dispersion prepared in step (1) is absorbed by superabsorbent polymer fine particles. The absorption amount is not particularly limited as long as it can be stably maintained for a long time. The absorbing method and device are not particularly limited, and known ones can be used.

Then, in the step (3), the super-absorbent polymer fine particles prepared in the step (2) are dispersed in an oil-based dispersion medium, and the super-absorbent polymer fine particles carrying the super-absorbent water-soluble polymer particles are contained in the variable color dye composition. make. At this time, the dispersion amount is not particularly limited as long as it can be stably maintained. The method and device for dispersing are not particularly limited, and known ones can be used.

To the variable color pigment composition of the present invention, known fillers such as silica, alumina and mica, carbon powders, pigments, dyes, polymerization inhibitors, etc. are added to the extent that the effects of the present invention are not impaired.
Thickener, thixotropic agent, precipitation inhibitor, antioxidant,
A dispersant, a surfactant and the like can be added.

The variable color dye composition of the present invention is, for example, brushed, roll coated, kiss coat, wheeler coat, spray method, curtain coating method, dipping method, electrostatic coating method, gravure coater, gravure offset coater, flat plate. Offset coater, dilitho coater, flexo, air knife coater, bar coater, letterpress printing,
Apply the coating to the specified part or all of the surface of the object by coating means such as intaglio printing or silk screen printing, and if necessary, dry and cure to form a coating film, pattern, pattern, etc. that adheres to the object. can do.

The object used in the present invention may be an organic material, an inorganic material, or a combination thereof, and may be a naturally derived material, a synthetic material, or a combination thereof. Specifically, for example, ordinary paper is used. other,
Synthetic paper or a synthetic film of polyethylene, polyethylene terephthalate having transparency, polypropylene, vinyl chloride or the like can also be used, and carbon, glass, ceramics, metal, wood, or combinations thereof, and processed products thereof, etc. Can be mentioned. In order to improve the adhesion of the coating film, the surface of these objects can be subjected to surface treatment such as matting treatment and corona treatment. The amount of coating on the surface of the object is not particularly limited, but an example of about 1 to 30 g / m ² can be given.

Using the variable color dye composition of the present invention, at least the substrate is subjected to at least a printing method such as letterpress printing, intaglio printing such as gravure printing, lithographic printing such as offset printing, screen printing and ink jet printing, and other commonly used printing methods. Apply to one side of the specified part, dry if necessary,
It is possible to form the anti-counterfeit sheet of the present invention having an identification code for authenticity determination, which is cured by irradiation with light such as ultraviolet rays.

The base material used in the present invention includes high quality paper, art paper, coated paper, mirror coated paper, condenser paper,
In addition to paraffin paper and other paper, in addition to paper and film with an overcoat layer (protective layer) on it, synthetic paper or synthetic films such as polyethylene, transparent polyethylene terephthalate, polypropylene, vinyl chloride, etc. It can also be used. When using these synthetic films, it is preferable to subject the surface of the base material to a surface treatment such as a mat treatment or a corona treatment. The coating amount on the substrate surface is not particularly limited, but is, for example, 1 to 30 g /
m ² is preferably 3 to 20 g / m ² , more preferably 5 to 15 g / m ² .

The present invention will be described in more detail below with reference to the drawings. FIG. 1 shows an identification code for authenticity determination, which is obtained by coating a base material with a variable color dye composition containing superabsorbent polymer fine particles carrying a variable color dye whose color tone reversibly changes with or without oxygen according to the present invention. It is explanatory drawing which shows an example of the applied anti-counterfeit sheet (receipt) of this invention. In FIG. 1, the anti-counterfeit sheet 1 of the present invention comprises a base material sheet 2 and a predetermined item 3
Designed pattern 4 for the purpose of overall decoration
Is printed with the variable color dye composition of the present invention, and the identification code 5 for authenticity determination having the same pattern as the pattern 4 is applied. The identification code 5 for authenticity determination is the variable color dye composition. Shows the color tone in the aerobic state. In addition,
The color tone of the pattern 4 is tint block printed with a general ink having the same color tone as that of the variable color dye composition in the aerobic state. That is, in the normal state, since the pattern 4 and the authenticity determining identification code 5 have the same color tone, they cannot be visually distinguished, and in this state, the authenticity determining identification code 5 is in the concealed state.

When judging the authenticity of the anti-counterfeit sheet 1, as a method for converting the aerobic state to the anoxic state, for example, the anti-counterfeit sheet 1 is placed in a vacuum chamber (not shown), nitrogen gas or the like is used. By selectively spraying the identification code 5 for authenticity determination to realize an anoxic environment, or if the oxygen concentration of the region including the identification code 5 for authenticity determination is made extremely low in a spot state, the authenticity determination is performed. The identification code 5 for use changes from the color tone of the aerobic state to the color tone of the anoxic state, and the difference from the color tone of the pattern 4 becomes clear and becomes apparent. This manifestation can be confirmed visually, but it can also be read by an optical mechanical reader. For such an authenticity judgment method, select an appropriate one depending on the characteristics and use situation of the anti-counterfeit sheet, such as a relatively expensive bond or an admission ticket that requires a large number of authenticity judgments immediately. Preferably.

In the forgery prevention sheet 1 of the present invention,
The authenticity identification code 5 is usually formed so as to be capable of intimately contacting the atmosphere, but the surface is not provided with any coating, and the surface is directly exposed to the atmosphere. It may be coated with a transparent film.
At that time, at least a part of the transparent film may be composed of a perforated film. For example, the surface may be covered with a porous transparent film having fine holes.

FIG. 2 is an explanatory view showing an example of another forgery prevention sheet (receipt) of the present invention, and FIG. 3 of the other forgery prevention sheet (receipt) of the present invention shown in FIG. It is an AA line sectional explanatory view. In FIG. 2, the anti-counterfeit sheet 1A of the present invention includes a base material sheet 2 on which predetermined items 3 and a designed pattern 4 intended for overall decoration are printed, and a variable color of the present invention. When printed using the dye composition, the identification code 5 for authenticity determination having the same pattern as the pattern 4 is applied,
As shown in FIGS. 2 and 3, the authenticity identification code 5 is covered with an oxygen-impermeable transparent film 6 in an oxygen-free state, and the color tone of the variable color dye composition in the covered region is in the oxygen-free state. Has the color tone of. As shown in FIG. 2, the identification code 5 for authenticity determination is adhered to the base material 2 by the pressure sensitive adhesive 7 applied to the periphery of the transparent film 6, and the covered portion is completely shielded from the atmosphere. It is in the state of being The color tone of the pattern 4 is printed with a tint pattern with a general ink having the same color tone as the color tone of the variable color dye composition in the anoxic state. That is, in the normal state, since the pattern 4 and the identification code 5 for authenticity determination have the same color tone, they cannot be visually distinguished, and in this state, the identification code 5 for authenticity determination is in the concealed state. As the oxygen impermeable transparent film 6, for example, a biaxially stretched film (Eval EF-XL / 15 μm manufactured by Kuraray Co., Ltd.) is used, and the substrate 2 is
Roll-coated varnish ink is provided as a coat layer on the surface, and high-quality paper processed to prevent oxygen from entering is used.

Then, at the time of authenticity judgment, the transparent film 6
When, for example, is peeled off, the variable color dye composition coated in the authenticity identification code 5 comes into contact with oxygen in the air, and the color tone changes from an anoxic state to an aerobic state, resulting in a pattern 4 The difference becomes clear, and the identification code 5 for authenticity judgment becomes apparent. This manifestation can be confirmed visually, but it can also be read by an optical mechanical reader.

Although it can be easily inferred that the identification code 5 for authenticity determination is provided in the portion covered with the transparent film 6, for example, in the anoxic state, a colorless (white) variable color dye composition is used. If the identification code 5 for authenticity determination is provided by using an object, or if it is colored as described above, the color tone of the background of the identification code 5 for authenticity determination is the same as the color tone of the identification code 5 for authenticity determination. With this, the concealing property of the authenticity determining identification code 5 can be achieved, and forgery thereof can be made more difficult.

FIG. 4 is an explanatory view schematically showing a state in which the variable color dye composition containing the super absorbent polymer particles carrying the variable color dye of the present invention is applied to an object. In FIG. 4, 10 is an object, 12 is a coating film formed by applying the variable color dye composition of the present invention on the object 10, and 13 is high water absorption absorbing a solution and / or dispersion liquid of the variable color dye 14. 2 shows fine polymer particles. Since the color tone of the variable color pigment 14 carried on the superabsorbent polymer fine particles 13 in the coating film 12 reversibly changes depending on the presence or absence of oxygen as described above, the object 10 is placed in the air, for example. In some cases, it has a color tone in the aerobic state. Therefore, it can be used for authenticity determination of the object 10 in the same manner as in the case of the anti-counterfeit sheet 1 shown in FIG. 1, and the object 10 seems to be full or stagnant with carbon dioxide gas, nitrogen, etc. When you put it in an atmosphere such as a tank or a cave, its color tone changes from aerobic state to anoxic state, and you can check it visually, so you can detect the presence of oxygen gas and avoid danger. It can also be used for.

Since the present invention is not limited to the above embodiment, various modifications can be made without departing from the spirit of the claims.

[0054]

The variable color dye composition containing fine water-absorbent polymer particles carrying the variable color dye according to claim 1 of the present invention is a solution of the variable color dye whose color tone reversibly changes depending on the presence or absence of oxygen. Since / or the superabsorbent polymer fine particles having absorbed the dispersion liquid are dispersed in an oil dispersion medium, they are inexpensive and have good storability, and can be easily applied to an object by a known method such as printing, and the coating film is It is remarkable that it is possible to detect the presence or absence of oxygen gas by utilizing the fact that the color tone reversibly changes depending on the presence or absence of oxygen, and to perform the authenticity determination of the object without using a special authenticity determination device. Produce an effect.

The variable color dye composition according to claim 2 of the present invention is the variable color dye composition according to claim 1, wherein the superabsorbent polymer fine particles are spherical fine particles. The composition has the same effect as that of the composition, and even when it absorbs water, it is non-adhesive to each other, has excellent handleability, and has an even more remarkable effect of being excellent in smoothness of the coating film surface.

By the production method according to claim 3 of the present invention, a remarkable effect that the variable color dye composition of the present invention can be easily produced is exhibited.

The anti-counterfeit sheet according to claim 4 of the present invention is an authenticity judgment formed by using the variable color dye composition according to claim 1 or 2 on a predetermined portion of at least one surface of a substrate. Since the identification code for authenticity is applied, the identification code for authenticity determination is maintained in the color tone in the aerobic state, and the identification code for authenticity determination is used in the atmosphere without oxygen (or extremely low) in the authenticity determination. By exposing the inside, the color tone of the identification code for authenticity determination is changed to the color tone in the anoxic state, and this color change is configured to be confirmed visually or by optical mechanical reading. It can be easily and easily confirmed by dynamic mechanical reading, is excellent in cost and productivity, and is also excellent in concealing the identification code for authenticity determination. The forgery prevention sheet according to claim 4 of the present invention includes receipts, forms such as securities, IC cards, magnetic cards, and rewrite cards.

The anti-counterfeit sheet according to claim 5 of the present invention is the anti-counterfeit sheet according to claim 4, in which at least a part of the identification code for authenticity determination is made oxygen-free by an oxygen-impermeable transparent film. The color tone of the variable color dye composition in the coated region is the color tone in the anoxic state, and therefore the transparent film is peeled or damaged at the time of authenticity determination, and the atmosphere. By changing the color tone of the identification code for authenticity judgment into the color tone in the aerobic state by contacting the oxygen in it with the variable color dye composition, and confirming this color tone change visually or by optical mechanical reading. Therefore, no special device for revealing the identification code for authenticity determination is required at the time of authenticity determination, and it can be easily and visually confirmed by visual inspection or optical mechanical reading. In addition, the cost and productivity are excellent, and the difficulty of creating counterfeit products and falsification of genuine products is high, and in addition, the concealment of the code for authenticity determination is also excellent. Play.

The counterfeiting prevention sheet according to claim 6 of the present invention is the anti-counterfeit sheet according to claim 4, wherein the authenticity determining identification code is exposed to an atmosphere containing no oxygen when determining authenticity. 5. The forgery prevention according to claim 4, wherein the color tone of the variable color pigment composition changes from the color tone in the aerobic state to the color tone in the anoxic state, and the color tone change can be visually recognized or optically mechanically read. In addition to producing the same effect as the use sheet, it has a further remarkable effect that it is more difficult to create a counterfeit product or falsify a genuine product.

The anti-counterfeit sheet according to claim 7 of the present invention is the anti-counterfeit sheet according to claim 5, which is covered with the oxygen-impermeable transparent film so as to be in an oxygen-free state when judging authenticity. When the exposed region is exposed to an atmosphere containing oxygen, the color tone of the variable color dye composition in the covered region changes from the color tone in the anoxic state to the color tone in the aerobic state, and the color tone change is visually recognized. Since it is readable by an optical machine, it has the same effect as that of the anti-counterfeit sheet according to claim 5, and has a further remarkable effect that it is more difficult to create a counterfeit product or falsify an authentic product. Play.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of a forgery prevention sheet of the present invention.

FIG. 2 is an explanatory view showing an example of another forgery prevention sheet of the present invention.

FIG. 3 is a cross-sectional view taken along the line AA of the other forgery prevention sheet of the present invention shown in FIG.

FIG. 4 is an explanatory diagram schematically showing a state in which a variable color dye composition containing fine water-absorbent polymer particles carrying a variable color dye of the present invention is applied to an object.

[Explanation of symbols]

1, 1A Anti-counterfeit sheet of the present invention 2 Base paper 3 prescribed matters 4 patterns 5 Identification code for authenticity judgment 6 transparent film 7 Pressure-sensitive adhesive 10 objects 12 coating 13 Super absorbent polymer particles 14 Variable color pigment

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G01N 31/22 122 G01N 31/22 122 G06K 19/077 G07D 7/12 // G07D 7/12 G06K 19 / 00 K F term (reference) 2C005 HA03 HB09 HB10 JB17 KA01 KA06 LA02 LA12 2G042 AA05 BB09 CA10 CB06 DA03 DA08 EA20 FA02 FA05 FA13 FB07 FC02 FC06 FC08 GA05 HA07 2G054 A05 GB04 A05 FB01 A04 FB04 GA05 A04 FB04 GA02 A04 FB02 GA04 GA02 A04 FB02 GA04 A02 FB02 GA04 GA02 A04 FB02 GA04 A04 FB02 A04 FB02 GA03 A02 DB01 5B035 AA13 BA03 BB09 CA01

Claims (7)

[Claims] 1. A variable color characterized in that superabsorbent polymer fine particles having absorbed a solution and / or a dispersion of a variable color dye whose color tone reversibly changes depending on the presence or absence of oxygen are dispersed in an oil dispersion medium. A variable color dye composition comprising superabsorbent polymer particles carrying a dye. 2. The variable color dye composition according to claim 1, wherein the superabsorbent polymer fine particles are spherical fine particles. 3. A method for producing a variable color dye composition comprising superabsorbent polymer fine particles carrying a variable color dye, which is produced by the following steps (1) to (3). (1) A solution and / or a dispersion is prepared by dissolving and / or dispersing a variable color dye whose color tone reversibly changes depending on the presence or absence of oxygen. (2) The superabsorbent polymer fine particles are allowed to absorb the solution and / or dispersion prepared in the step (1). (3) The super absorbent polymer particles prepared in step (2) are dispersed in an oil dispersion medium to prepare a variable color dye composition containing super absorbent polymer particles carrying a variable color dye. 4. An authenticity determining identification code formed by using the variable color dye composition according to claim 1 or 2 is provided on a predetermined portion of at least one surface of the base material. Anti-counterfeit sheet. 5. At least a part of the authenticity identifying code is covered with an oxygen-impermeable transparent film so as to be in an oxygen-free state, and the color tone of the variable color dye composition in the covered region is changed. The anti-counterfeit sheet according to claim 4, exhibiting a color tone in the anoxic state. 6. The color tone of the variable color dye composition changes from a color tone in an aerobic state to a color tone in an anoxic state when the authenticity determining identification code is exposed to an atmosphere containing no oxygen in authenticity determination. 5. The anti-counterfeit sheet according to claim 4, wherein the anti-counterfeit sheet is changed and the change in color tone can be visually recognized or read by optical mechanical reading. 7. In the authenticity determination, when a region covered by the oxygen-impermeable transparent film to be in an anoxic state is exposed to an atmosphere containing oxygen, the variable color of the covered region is changed. 6. The forgery prevention according to claim 5, wherein the color tone of the dye composition changes from the color tone in the anoxic state to the color tone in the aerobic state, and the change in the color tone can be visually recognized or optically mechanically read. Sheet.